EP3085428B1 - Filter element and filter assembly - Google Patents

Description

Technical field

The present invention relates to a filter element and a filter arrangement.

State of the art

Known air filters for vehicles can be formed from a filter medium wound or folded onto a center tube. Particularly in the area of agricultural and construction vehicles, the filter medium can become clogged or damaged due to the high level of dust. This can reduce the service life and the filter efficiency of the air filter. To ensure filter efficiency over the life of the filter element, a reliable seal of the filter element against a filter holder is also required.

Out DE 10 2014 006850 A1 an oval hollow filter element is known. Out US 2012/240767 A1 a gas-liquid separator with a cross section with a long and a short axis is known. Out EP 0 923 975 A1 an air filter with an oval, tapered filter element is known.

The WO 2009/106591 A2 describes an air filter with a pre-separator. With the help of the pre-separator, particles contained in the raw gas can be separated using centrifugal force. This can increase the filter efficiency since the particles are separated from the raw gas before reaching the air filter. The air filter has an oval sealing device with straight and curved sections.

Disclosure of the invention

Against this background, the present invention is based on the object of specifying an improved filter element.

Accordingly, a filter element having an oval cross section in a longitudinal direction thereof is proposed. The filter element comprises a circumferential sealing device for, in particular radially, sealing the filter element with respect to a filter receptacle for the filter element, the sealing device having two first curvature sections arranged opposite one another and two second curvature sections arranged opposite one another, the first curvature sections each having a first radius of curvature and the second Curvature sections each have a second radius of curvature and the first radius of curvature differs from the second radius of curvature. Designing the seal exclusively with two different radii, which are each completely or at least substantially constant over the individual curvature sections, can have advantages with regard to tool manufacture and quality control.

The second radius of curvature can go towards infinity, ie can also be straight, and this also applies analogously to an oval shape of the filter element. In one embodiment, the sealing device has an essentially stadium-like geometry. It has proven to be advantageous that the sealing device does not have straight sections but only curved sections. This comes in particular then to be used if the filter element or the filter body formed from a filter medium has an oval cross-section, the outer contour of which has partially straight or slightly curved sections. Because the sealing device has essentially exclusively curved sections, a constant contact pressure of the sealing device against an engagement area of the filter receptacle can be achieved over the entire circumference of the sealing device. The sealing device is preferably designed to seal the filter element radially inwards with respect to the filter receptacle. Stronger curvatures or smaller radii on the sealing device are more advantageous for radial sealing inwards or outwards than weaker curvatures or larger radii, since with increasing curvature the risk decreases that the sealing device loses contact with a sealing contact surface on the filter receiving side when subjected to vibrations. As an alternative or in addition, the sealing device can also be set up to axially seal the filter element with respect to the filter receptacle. In the present case, “inward” is to be understood as a direction to be oriented radially towards a fluid outlet of the filter holder. The sealing device is preferably resiliently deformable. The filter element can spatially surround a secondary element. The sealing device preferably runs completely around a first end plate of the filter element. The filter element is preferably an air filter for filtering intake air for an internal combustion engine. The filter element is preferably used in motor vehicles, trucks, construction vehicles, water vehicles, rail vehicles, agricultural machines or vehicles or aircraft.

According to the idea of the invention, it is advantageous, but not absolutely necessary, to choose a course of the sealing device, which in particular is formed exclusively from circular sections. A significant advantage arises from the fact that the sealing device has only curved sections, in particular continuously curved in one direction, so that a continuously convex outer contour is created without straight or concave sections. Therefore, in a more general form, the invention also relates to a filter element, comprising an oval cross-section defined by a filter body made of a filter medium with two first opposing curvature sections with greater curvature, which are connected to one another by two second opposing curvature sections compared to the first curvature sections Filter element further comprising an oval circumferential sealing device for, in particular, radial sealing of the filter element with respect to a filter receptacle, the sealing device having two first curvature sections with a greater curvature and two curvature sections that are arranged opposite to each other and less curved than the first curvature sections, the second curvature sections of the sealing device are more curved than the second curved sections of the through the fil body defined oval cross section. According to the invention, the first curvature sections are connected to one another by the second curvature sections in such a way that first and second curvature sections each merge, in particular merge directly, preferably continuously and more preferably smoothly merge. This has the consequence, for example, that in the transition region between the first and second curvature sections there can be no further curvature section with a curvature that is greater than the curvature of the two first curvature sections. This has the advantage that, despite the non-circular shape, an all-round good sealing effect can be ensured. According to the invention an oval course is chosen for the density submission, which has a center point and two axes of symmetry intersecting in it. For the filter body and / or at least one of the end disks, an oval cross section or course is preferably selected, which has a center point and two axes of symmetry intersecting in it and / or a width to height ratio of more than 1.5: 1, preferably more than 2: 1, more preferably less than 5: 1 or 4: 1, particularly preferably less than 3: 1. Width-to-height ratios of the filter element and / or filter body in the range between 1.5: 1 and 3: 1 are particularly advantageous for a pre-separation effect by centrifugal force. The filter body and sealing device particularly preferably have the same axes of symmetry. The filter element particularly preferably has a symmetry longitudinal axis, to which the sealing device and / or the filter body and / or at least one end plate are at least substantially symmetrical. This longitudinal axis of symmetry preferably runs through the intersection of the intersecting axes of symmetry mentioned above, preferably in each case perpendicular to these. The longitudinal axis of symmetry is preferably coaxial with the central axis of the filter holder and / or filter element or can be defined by the latter.

According to the invention, it is provided that the second curvature sections of the sealing device are curved more than a comparison curve, which is comparable with regard to its position on the end disk and is essentially parallel, in particular concentric, with the inner and / or outer contour of the open end disk and / or filter body Embodiments that the second curvature sections of the sealing device and the second curvature sections of the oval cross-section defined by the filter body are arranged adjacent to one another, ie have essentially the same angular position with respect to the oval shape. The same applies to the first, more curved than the second
Curvature sections of the sealing device and the cross section defined by the filter body.

In embodiments, centers of curvature of the first radii of curvature are arranged on a first straight line, centers of curvature of the second radii of curvature are arranged on a second straight line and the first straight line is positioned perpendicular to the second straight line. The second radii of curvature are preferably larger than the first radii of curvature. The first radii of curvature are preferably the same size. The second radii of curvature are preferably the same size.

In further embodiments, the second straight line is arranged centrally between the centers of curvature of the first radii of curvature and / or the first straight line is arranged centrally between the centers of curvature of the second radii of curvature. End points of the straight line are defined by the centers of curvature. The first straight line preferably divides the second straight line in the middle and vice versa.

A filter element according to the invention has a filter body formed from a filter medium. The filter body can preferably be flowed through radially from the outside inwards or vice versa. The filter body is formed by a zigzag-folded, annularly closed filter medium and has an oval shape.

According to the invention, the filter element has at least one end plate and a filter body connected to the end plate, the sealing device being provided on a front side of the in particular open end plate facing away from the filter body. The end plate is preferably a first end plate of the filter element. The filter element preferably has two end disks, between which the filter body is arranged. The sealing device can be formed in one piece with the first end plate. The second end plate can preferably be made closed.

In further embodiments, an outer contour and / or inner contour of the sealing device is not arranged parallel to an outer contour and / or inner contour of the end plate. Preferably, the outer or inner contour of the sealing device does not follow the outer or inner contour of the end plate, i. H. the distance between the outer contour of the sealing device and the outer contour of the end plate is not constant. More preferably, the sealing surface follows, i.e. the contact surface of the sealing device for sealing contact with a corresponding sealing contact surface of the housing, not the outer contour of the end plate. In the case of a radial seal, this generally relates to the radial inner surface of the sealing device, but the radial outer surface of the sealing device can also form the sealing surface. Particularly preferably, the sealing device, in particular the inner surface of the seal, has a smaller distance from the outer (in particular radially outer) outer surface of the filter body and / or the outer contour of an open end plate in the middle of the less curved curvature sections of the filter body and / or the sealing device Transition area between strongly and slightly curved curvature sections of the filter body and / or the sealing device. As a result, the curvature of the seal in the weakly curved area of the filter body can be strengthened and thus optimized with regard to the reliability of the seal when subjected to vibrations. Geometrically, this preferably has the consequence that the curvature of the second curvature sections of the seal cannot be constructed either by scaling up / down (central extension) of the outer contour of the open end plate and / or the filter body. Rather, this preferably means that, as provided in accordance with the invention, the curvature of the second curvature sections of the seal is stronger than the curvature of a comparable, in particular concentric and, in particular, concentric and, in particular, obtained from the outer contour by scaling down, which is parallel to the outer contour of the filter body and / or open end plate Outer contour and parallel to this comparison curve, which is at least substantially the same distance from the outer contour of the end plate and / or filter body in the middle of the second curvature sections of the seal, the outer contour of the end plate and / or the outer contour of the filter body.

In an advantageous embodiment, the sealing device is arranged in the longitudinal direction within an imaginary axial continuation of the outer lateral surface of the filter body and / or the outer contour of an open end disk. This has the advantage that the sealing device does not require any additional installation space radially to the longitudinal direction and can be formed directly, for example in one piece or with the same material as the end plate. If an annularly closed, zigzag or star-shaped filter bellows made of a filter medium is used as the filter body, it can be particularly advantageous that the sealing device is arranged within a cross section of the filter body (more precisely within an imaginary axial continuation of the cross section in the longitudinal direction). This has the advantage that the cross section of the outflow path from the filter element is not unnecessarily reduced by the sealing device, which would increase the flow resistance.

In further embodiments, the filter element has an inflow protection covering the filter body at least in sections. The flow protection prevents particles contained in the fluid to be filtered, such as small stones, from hitting the filter medium directly. This prevents damage to the filter medium. This increases the service life of the filter element.

In further embodiments, the flow protection is glued, welded or fused to the filter body. The flow protection is alternatively flush and preferably loosely on the filter medium, in particular the folded edges of the filter medium. In particular, the flow protection is arranged adjacent to a first end plate of the filter element. The flow protection can be connected to the first end plate, for example, in a form-fitting manner partially enclosed by its material. As a result, the flow protection can be firmly connected to the filter body by means of the end plate material, in particular polyurethane or polyurethane foam.

In further embodiments, the flow protection is fluid-tight. The flow protection can be a film. Alternatively, the flow protection can be permeable to fluid. For example, the flow protection can be made from a fine-mesh network or grid. The flow protection is preferably made of a plastic material.

The flow protection preferably runs completely around the filter body, in particular in a closed ring. This can ensure that a filter element that can be installed in two positions due to the symmetry is protected in both positions from a frontal inflow by a fluid inlet and / or that in both possible installation positions the formation of an important one for the pre-separation around the filter element is carried out in the same way rotating raw fluid flow can be formed. The flow protection should preferably extend completely, at least in the areas that can be exposed to direct flow, axially from the first end plate so far over the filter body that the axial extent of the fluid inlet of a filter housing is covered. Depending on the design of the filter system, this is the case if the flow protection extends over at least 15, 20 or 25% of the axial length of the filter body and / or a maximum of 80, 70, 60, 50, 40 or 30% of the axial length of the filter body.

Furthermore, a filter arrangement with such a filter holder and such a filter element is proposed, which is received in a receiving section of the filter holder.

In embodiments, the receiving section has an engagement area, into which a circumferential sealing device of the filter element engages, the sealing device abutting the engagement area with an inner surface. The engagement area is preferably provided circumferentially around a fluid outlet of the filter receptacle. The sealing device preferably lies on the inside against the engagement area.

Furthermore, a filter holder for a filter element that has an oval cross section transversely to a longitudinal direction thereof is proposed. The filter receptacle comprises a receptacle section for receiving the filter element, a fluid inlet for the inlet of fluid to be filtered into the filter receptacle, and a fluid outlet for the outlet of the fluid filtered with the aid of the filter element from the filter receptacle, the fluid inlet being arranged such that an inflow direction of the fluid to be filtered Fluid is oriented in the direction of an outer surface of the filter element that can be received in the receiving section, so that the fluid to be filtered flows tangentially around the filter element that can be received in the receiving section in order to separate particles contained in a wall of the receiving section in the fluid to be filtered with the aid of centrifugal force. The filter holder can also be referred to as a housing or filter housing.

Due to the fact that the inflow direction is oriented in the direction of the filter element, the flow against the filter element is direct compared to known arrangements. Since the filter holder itself acts as a pre-separator, in particular as a centrifugal separator, there is no need for additional pre-separators which are arranged upstream of the filter element. This results in a cost advantage over known arrangements. The particularly oval cross-sectional geometry of the receiving section leads to a favorable degree of pre-separation of the particles in comparison to a circular cross-sectional geometry. Furthermore, due to the oval cross-sectional geometry with the same construction volume, narrow or rectangular construction spaces can also be used to accommodate the filter holder. In particular, the filter holder is arranged such that a width direction of the holder section is positioned horizontally. The inflow direction of the fluid to be filtered is preferably oriented such that the fluid directly meets a curvature of the wall of the receiving section. As a result, the fluid is greatly accelerated. Compared to a receiving section with a circular cross-section, this leads to a favorable degree of pre-separation. In the present case, oval can be understood to mean a rectangular geometry with rounded corners, an at least approximately elliptical geometry or a geometry formed from a plurality of curvature sections or circular sections. An oval shape with two axes of symmetry, which intersect in particular orthogonally in a center, through which a central axis of the filter holder and / or filter element (s) perpendicular to the two axes of symmetry is preferred for both the filter holder and the filter elements and / or their sealing device. runs. Elliptical shapes can also be created by approximation constructions of ellipses, such as, for example, via circles of curvature or after de la hire. The receiving section preferably has a first and a second housing part, which can be connected to one another with the aid of fastening means. The housing parts can be made of a plastic material. The housing parts are preferably plastic injection molded components. Alternatively, the housing parts can also be made from sheet metal. The receiving section can also be formed in one piece. This means that the housing parts can be connected to one another in one piece. The particles can be, for example, sand, dust, parts of plants or the like.

In embodiments, the inflow direction of the fluid to be filtered is oriented perpendicular to the longitudinal direction of the filter element that can be accommodated in the receiving section. As a result, the filtering material flows Fluid partially into the space between the receiving section and the filter element and optionally at least partially directly onto the filter element and flows around it, preferably in a helical manner.

In further embodiments, the receiving section is set up to receive the filter element centrally in the receiving section with respect to a longitudinal direction thereof. A second end plate of the filter element can have bracing elements, with the aid of which the filter element can be optimally positioned in the receiving section. The elastically deformable bracing elements also serve to dampen vibrations and / or to compensate for tolerances.

In further embodiments, the receiving section is set up to receive the filter element in such a way that a constant distance is provided between the filter element and the wall of the receiving section perpendicular to the outer circumferential surface of the filter element and / or perpendicular to the inner wall of the receiving section. The distance is preferably substantially or completely constant over the longitudinal direction, but can also vary in the longitudinal direction. For example, the distance can decrease or increase in the longitudinal direction. For this purpose, the filter element can for example be tapered in the longitudinal direction in or against the outflow direction.

The filter element can be tapered in the longitudinal direction.

In further embodiments, the receiving section has a width direction and a height direction in cross section, which preferably correspond to axes of symmetry of the oval shape, the fluid inlet being arranged such that the inflow direction of the fluid is arranged perpendicular to the width direction. The fluid inlet is preferably arranged laterally on the receiving section, so that the inflowing fluid hits the wall of the receiving section.

In further embodiments, an expansion of the receiving section in the width direction is greater than in the height direction. For example, the receiving section is at least 1.5 times and preferably two to three times wider than high. The width-to-height ratio of the filter element provided for receiving in the receiving section is preferably greater than the width-to-height ratio of the receiving section. More preferably, a suitable filter element has a similar height to width ratio and in particular a shape such that perpendicular to the outer circumferential surface of the filter element and / or perpendicular to the inner wall of the receiving section, a constant distance between the filter element and the circumference around the filter element Wall of the receiving section is provided.

In further embodiments, the fluid inlet has an oval cross section with a larger diameter parallel to the longitudinal axis of the filter holder than perpendicular to the longitudinal axis. As a result, a small pressure loss can be achieved when the fluid to be filtered flows into the fluid inlet. Alternatively, the fluid inlet can have a circular cross section.

In further embodiments, the filter holder comprises a removable maintenance cover which has a particle discharge opening. The maintenance cover is preferably a plastic injection molded component. The maintenance cover can also be made from sheet metal. The maintenance cover can be fastened to the receiving section with quick-release fasteners. The particle discharge opening can have a valve.

In further embodiments, the maintenance cover has a tubular, in particular oval-tubular, flow protection which projects in particular into the interior of the filter receptacle and in which the filter element can be at least partially and preferably coaxially received. The flow protection is preferably formed in one piece with the maintenance cover. The length of the inflow protection is preferably designed such that it surrounds the filter element to about 15-50%, preferably 20-40%, of its total length in the longitudinal direction starting from the closed end plate, i.e. the length of the flow protection in the longitudinal direction is approximately 15-50%, preferably 20-40% of the length of the filter element.

Furthermore, a filter element is proposed which has an oval cross section transversely to a longitudinal direction thereof. The filter element comprises a first end plate, a second end plate and a filter body arranged between the first end plate and the second end plate, wherein the filter element can have a flow protection which at least partially covers the filter body. The filter element can have features mentioned above as well as below or in the claims.

The flow protection can also be provided on the receiving section. The flow protection prevents particles contained in the fluid to be filtered, such as sand, from hitting the filter medium directly. This prevents damage to the filter medium. This increases the service life of the filter element. The filter element is preferably an air filter for filtering intake air for an internal combustion engine. The filter element is preferably used in motor vehicles, trucks, construction vehicles, water vehicles, rail vehicles, agricultural machines or vehicles or aircraft. The filter medium is preferably folded in a zigzag shape. The filter medium is, for example, a filter paper, a filter fabric, a filter scrim or a filter fleece. In particular, the filter medium can be produced in a spunbonded or meltblown process. The filter medium can also be matted or needled. The filter medium can have natural fibers, such as cellulose or cotton, or synthetic fibers, for example made of polyester, polyvinyl sulfite or polytetrafluoroethylene. The fibers can be oriented in, obliquely and / or transversely to the machine direction or in a disordered manner during processing. The filter medium can be fused, glued or welded to the end disks

In embodiments, the flow protection is glued, welded or fused to the filter body formed from the filter medium. The flow protection is alternatively flush and preferably loosely on the filter medium, in particular the folded edges of the filter medium. In particular, the flow protection is arranged adjacent to a first end plate of the filter element. The flow protection can be connected to the first end plate, for example, in a form-fitting manner partially enclosed by its material.

In further embodiments, the flow protection is fluid-tight. The flow protection can be a film. Alternatively, the flow protection can be permeable to fluid. For example, the flow protection can be made from a fine-mesh network or grid. The flow protection is preferably made of a plastic material.

In further embodiments, the filter element surrounds a secondary element, which can also be received in the filter receptacle. The filter element can also be referred to as the first filter element and the secondary element can be referred to as the second filter element. The first end plate of the filter element preferably has a receiving opening into which the secondary element can be inserted. At the same time, this receiving opening preferably represents the outflow cross section of the first filter element.

In further embodiments, the filter element has a sealing device which is provided on the preferably open first end disk, the sealing device being set up to seal the filter element with respect to a filter receptacle, in particular radially or axially, such that the filter element in the upstream or raw side of the outflow side or The clean side is separated. The sealing device is preferably formed in one piece with the first end plate. In particular, the first end plate and the sealing device can be made from a particularly cast polyurethane material, in particular a foamed polyurethane material. The sealing device is preferably resiliently deformable. The sealing device is preferably set up to seal the filter element radially inward with respect to the filter receptacle, that is to say in the direction of a fluid outlet of the filter receptacle, and preferably has an inwardly directed, annularly closed, in particular oval, sealing surface. The sealing device can also be set up to axially seal the filter element with respect to the filter receptacle.

Furthermore, a filter arrangement with a filter receptacle of this type and a filter element of this type accommodated in a receptacle section of the filter receptacle is proposed, wherein a fluid inlet of the filter receptacle is arranged such that an inflow direction of the fluid to be filtered is oriented in the direction of an outer surface of the filter element accommodated in the receptacle section, so that the fluid to be filtered flows around the filter element received in the receiving section tangentially and / or helically, in particular oval screw-shaped, in order to separate particles contained in the fluid to be filtered on a wall of the receiving section with the aid of centrifugal force.

The inflow direction of the fluid to be filtered is preferably oriented such that the fluid directly meets a curvature of the wall of the receiving section. As a result, the fluid is greatly accelerated, which increases the centrifugal forces acting on the fluid. This favors the degree of pre-separation of the particles. The filter arrangement can also be referred to as a two-stage filter, the first stage being formed by centrifugal force separation and the second stage being formed by a filter element.

Furthermore, a filter holder for a filter element according to the invention, which has an oval cross section transversely to a longitudinal direction thereof, is proposed. The filter receptacle comprises a receptacle section for receiving the filter element, a fluid inlet for the inlet of fluid to be filtered into the filter receptacle and a fluid outlet for outlet using the filter element filtered fluids from the filter receptacle, the fluid inlet being arranged in such a way that an inflow direction of the fluid to be filtered into the fluid inlet is oriented parallel to the longitudinal direction of the filter element, the fluid inlet having a guide element which is set up to flow the fluid to be filtered to deflect into the fluid inlet in such a way that it flows around the filter element which can be received in the receiving section in a spiral manner in order to separate particles contained in the fluid to be filtered on a wall of the receiving section with the aid of centrifugal force.

The guide element can be a guide blade. Because the fluid to be filtered flows around the filter element in a spiral, helical or helical shape, the filter holder acts as a pre-separator for separating the particles. This eliminates the need for additional pre-separators. As a result, the filter holder can be produced particularly inexpensively. The filter holder preferably has an oval cross section. The preferably oval cross-sectional geometry of the receiving section leads to a favorable degree of pre-separation of the particles compared to a circular cross-sectional geometry. Furthermore, due to the oval cross-sectional geometry, narrow or rectangular installation spaces can also be used to accommodate the filter holder. In particular, the filter holder is arranged such that a width direction of the holder section is positioned horizontally. The receiving section preferably has a first and a second housing part, which can be connected to one another with the aid of fastening means. The housing parts can be made of a plastic material or a metallic material. The housing parts are preferably plastic injection molded components. The receiving section can also be formed in one piece. This means that the housing parts form one component. The maintenance cover can preferably be removed from the receiving section.

In embodiments, the filter receptacle has a variety of fluid inlets. Each fluid inlet has at least one guide element. The guide elements are preferably designed as guide vanes.

In further embodiments, the fluid inlets are arranged evenly distributed over a circumference of the filter receptacle. The fluid inlets are preferably arranged at a uniform distance from one another. Alternatively, the fluid inlets can be arranged unevenly distributed.

In further embodiments, a respective angle of curvature of the guide elements changes over a circumference of the filter holder. Each guide element preferably has a first section oriented parallel to the inflow direction and a second section oriented obliquely to the inflow direction. The sections are inclined relative to one another in the angle of curvature. The angles of curvature of all guide elements can be the same. Alternatively, the guide elements can have different angles of curvature. For example, the angles of curvature can vary over the circumference of the filter holder.

In further embodiments, a respective inflow cross section of the fluid inlets changes over a circumference of the filter receptacle. The inflow cross section can be rectangular or round, for example. The degree of pre-separation can be optimized by varying the inflow cross-sections.

In further embodiments, the fluid inlet is arranged on a maintenance cover that can be removed from the filter receptacle. The fluid inlet is preferably an opening in the maintenance cover. The maintenance cover preferably also has the guide elements. The guiding elements are particular integrally formed with the maintenance cover. The maintenance cover can be attached to the filter holder using quick-release fasteners.

In further embodiments, the guide element is positioned such that it is arranged next to the filter element in the longitudinal direction. A plurality of guide elements is preferably arranged around the filter element. As a result, the space available for the filter holder can be optimally used by the filter element. The length of the filter element can thus approximately correspond to the length of the filter holder.

In further embodiments, the filter receptacle has a tubular inflow protection in which the filter element can be at least partially arranged. The inflow protection or the inflow frame is preferably fluid-tight.

In further embodiments, the inflow protection is formed in one piece with a maintenance cover of the filter holder and / or the filter holder. The maintenance cover is preferably an inexpensive plastic injection molded component. The maintenance cover can also be made from sheet metal.

Furthermore, a filter arrangement with such a filter holder and a filter element, which is received in a receiving section of the filter holder, is proposed.

Furthermore, a filter holder for a filter element according to the invention, which has an oval cross section transversely to a longitudinal direction thereof, is proposed. The filter receptacle comprises a receptacle section for receiving the filter element, a fluid inlet for inlet of fluid to be filtered into the filter receptacle, and a fluid outlet for the outlet of the fluid filtered with the aid of the filter element from the filter receptacle, the fluid outlet being arranged such that an outflow direction of the filtered fluid is oriented parallel to the longitudinal direction of the filter element from the fluid outlet and wherein the fluid outlet has a circular cross section facing away from the filter element and an oval cross section facing the filter element.

This reduces a pressure loss when the filtered fluid flows out. This increases the efficiency of a filter arrangement with such a filter holder. The oval cross section preferably has a smaller height than the diameter of the circular cross section.

In embodiments, the circular cross-section and the oval cross-section of the fluid outlet have the same cross-sectional area. This allows the filtered fluid to flow freely. The oval cross-section can also have a larger cross-sectional area than the circular cross-section.

In further embodiments, the fluid outlet has a curved transition section which connects the circular cross section of the fluid outlet with the oval cross section of the fluid outlet. The transition cross section is preferably S-shaped.

In further embodiments, the fluid inlet widens in a width direction of the filter element from the circular cross section to the oval cross section. A width of the oval cross section is preferably greater than a diameter of the circular cross section.

In further embodiments, the fluid inlet constricts in a height direction of the filter element from the circular cross section to the oval cross section. A height of the oval cross section is preferably smaller than a diameter of the circular cross section.

In further embodiments, the filter receptacle has a tubular inflow protection in which the filter element can be at least partially accommodated. The inflow protection or the inflow frame is preferably fluid-tight.

In further embodiments, the flow protection is formed in one piece with a maintenance cover that can be removed from the filter holder. The maintenance cover is preferably an inexpensive plastic injection molded component. Alternatively, the maintenance cover can be made, for example, of sheet metal, in particular sheet steel.

Furthermore, a filter element is proposed which has an oval cross section transversely to a longitudinal direction thereof. The filter element comprises a first end plate, a second end plate and a filter body arranged between the first end plate and the second end plate, a cross section of the filter body on the second end plate being larger than a cross section of the filter medium on the first end plate. The filter element can have one or more of the features described above or below or in the claims.

The inside of the filter body preferably tapers conically. This enables an enlarged fluid outlet opening of the filter element compared to a non-tapered filter body. In this way, the transition section of the fluid outlet can be optimized, since the height of the oval cross section of the fluid outlet can be approximated to the diameter of the circular cross section of the fluid outlet. This leads to a further reduced pressure loss. The filter element is preferably an air filter element for filtering intake air for an internal combustion engine. The filter element is preferably used in motor vehicles, trucks, construction vehicles, water vehicles, rail vehicles, agricultural machines or vehicles or aircraft.

In embodiments, the cross section of the filter body increases continuously from the first end plate in the direction of the second end plate. The filter element can surround a secondary element that can be received in the filter receptacle. Corresponding to the filter body of the first filter element, the secondary element can have a conical or frustoconical geometry.

Furthermore, a filter arrangement with such a filter holder and such a filter element and / or secondary element is proposed, which is received in a receiving section of the filter holder.

Further possible implementations of the invention also include combinations of features or method steps described above or below with reference to the exemplary embodiments that are not explicitly mentioned. The person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

Further embodiments of the invention are the subject of the subclaims and the exemplary embodiments of the invention described below. Furthermore, the invention is explained in more detail using exemplary embodiments with reference to the accompanying figures.

Brief description of the drawings

Fig. 1:

eine schematische perspektivische Ansicht einer Ausführungsform einer Filteranordnung;

Fig. 2:

eine schematische Ansicht der Filteranordnung gemäß Fig. 1;

Fig. 3:

eine schematische Ansicht der Filteranordnung gemäß Fig. 1;

Fig. 4:

eine schematische Teilschnittansicht der Filteranordnung gemäß Fig. 1;

Fig. 5:

eine schematische Teilschnittansicht der Filteranordnung gemäß Fig. 1;

Fig. 6:

eine schematische perspektivische Ansicht eines für das Verständnis der Erfindung hilfreichen Filterelements;

Fig. 7:

eine schematische perspektivische Ansicht einer Ausführungsform eines Sekundärelements;

Fig. 8:

eine schematische Ansicht der Filteranordnung gemäß Fig. 1;

Fig. 9:

eine schematische Schnittansicht der Filteranordnung gemäß der Schnittlinie IX-IX der Fig. 8;

Fig. 10:

eine schematische Schnittansicht der Filteranordnung gemäß der Schnittlinie X-X der Fig. 8;

Fig. 11:

eine schematische Teilschnittansicht der Filteranordnung gemäß Fig. 1;

Fig. 12:

eine schematische perspektivische Ansicht einer weiteren Ausführungsform einer Filteranordnung;

Fig. 13:

eine schematische perspektivische Ansicht einer weiteren Ausführungsform einer Filteranordnung;

Fig. 14:

eine schematische perspektivische Ansicht einer weiteren Ausführungsform eines Filterelements;

Fig. 15:

eine schematische Schnittansicht des Filterelements gemäß Fig. 14;

Fig. 16:

eine schematische Ansicht des Filterelements gemäß Fig. 14;

Fig. 17:

eine schematische Teilschnittansicht des Filterelements gemäß Fig. 14;

Fig. 18:

eine schematische Teilschnittansicht einer weiteren Ausführungsform eines Filterelements;

Fig. 19:

eine schematische Teilschnittansicht einer weiteren Ausführungsform einer Filteranordnung;

Fig. 20:

eine schematische perspektivische Ansicht einer weiteren Ausführungsform einer Filteranordnung;

Fig. 21:

eine schematische perspektivische Teilschnittansicht der Filteranordnung gemäß Fig. 20;

Fig. 22:

eine schematische Teilschnittansicht der Filteranordnung gemäß Fig. 20;

Fig. 23:

eine schematische Schnittansicht der Filteranordnung gemäß Fig. 20;

Fig. 24:

eine schematische Teilschnittansicht der Filteranordnung gemäß Fig. 20;

Fig. 25:

eine schematische Ansicht der Filteranordnung gemäß Fig. 20;

Fig. 26:

eine schematische perspektivische Ansicht einer weiteren Ausführungsform einer Filteranordnung;

Fig. 27:

eine für das Verständnis der Erfidnung hilfreiche, schematische Ansicht einer Filteranordnung;

Fig. 28:

eine schematische Schnittansicht der Filteranordnung gemäß Fig. 26;

Fig. 29:

eine schematische Schnittansicht der Filteranordnung gemäß Fig. 26;

Fig. 30:

eine schematische Schnittansicht der Filteranordnung gemäß Fig. 26

Fig. 31:

eine schematische Schnittansicht der Filteranordnung gemäß Fig. 26; und

Fig. 32:

eine schematische Teilschnittansicht der Ausführungsform einer Filteranordnung gemäß Fig. 19 ohne Abbildung des Filterelements.

It shows:

Fig. 1:

a schematic perspective view of an embodiment of a filter arrangement;

Fig. 2:

a schematic view of the filter arrangement according to Fig. 1 ;

Fig. 3:

a schematic view of the filter arrangement according to Fig. 1 ;

Fig. 4:

is a schematic partial sectional view of the filter arrangement according to Fig. 1 ;

Fig. 5:

is a schematic partial sectional view of the filter arrangement according to Fig. 1 ;

Fig. 6:

a schematic perspective view of a filter element useful for understanding the invention;

Fig. 7:

a schematic perspective view of an embodiment of a secondary element;

Fig. 8:

a schematic view of the filter arrangement according to Fig. 1 ;

Fig. 9:

is a schematic sectional view of the filter assembly according to section line IX-IX of the Fig. 8 ;

Fig. 10:

is a schematic sectional view of the filter assembly according to section line XX of the Fig. 8 ;

Fig. 11:

is a schematic partial sectional view of the filter arrangement according to Fig. 1 ;

Fig. 12:

a schematic perspective view of a further embodiment of a filter arrangement;

Fig. 13:

a schematic perspective view of a further embodiment of a filter arrangement;

Fig. 14:

a schematic perspective view of a further embodiment of a filter element;

Fig. 15:

is a schematic sectional view of the filter element according to Fig. 14 ;

Fig. 16:

a schematic view of the filter element according to Fig. 14 ;

Fig. 17:

is a schematic partial sectional view of the filter element according to Fig. 14 ;

Fig. 18:

a schematic partial sectional view of a further embodiment of a filter element;

Fig. 19:

a schematic partial sectional view of a further embodiment of a filter arrangement;

Fig. 20:

a schematic perspective view of a further embodiment of a filter arrangement;

Fig. 21:

is a schematic perspective partial sectional view of the filter assembly according to Fig. 20 ;

Fig. 22:

is a schematic partial sectional view of the filter arrangement according to Fig. 20 ;

Fig. 23:

is a schematic sectional view of the filter arrangement according to Fig. 20 ;

Fig. 24:

is a schematic partial sectional view of the filter arrangement according to Fig. 20 ;

Fig. 25:

a schematic view of the filter arrangement according to Fig. 20 ;

Fig. 26:

a schematic perspective view of a further embodiment of a filter arrangement;

Fig. 27:

a schematic view of a filter arrangement helpful for understanding the invention;

Fig. 28:

is a schematic sectional view of the filter arrangement according to Fig. 26 ;

Fig. 29:

is a schematic sectional view of the filter arrangement according to Fig. 26 ;

Fig. 30:

is a schematic sectional view of the filter arrangement according to Fig. 26

Fig. 31:

is a schematic sectional view of the filter arrangement according to Fig. 26 ; and

Fig. 32:

is a schematic partial sectional view of the embodiment of a filter arrangement according to Fig. 19 without image of the filter element.

In the figures, identical or functionally identical elements have been provided with the same reference numerals, unless stated otherwise.

Embodiment (s) of the invention

The Fig. 1 shows a schematic perspective view of an embodiment of a filter arrangement 1. Die Fig. 2 shows a front view of the filter arrangement 1. Die Fig. 3 shows a side view of the filter assembly 1. Die Fig. 4 and 5 each show partial sectional views of the filter arrangement 1.

The filter arrangement 1 comprises a filter holder 2 and a filter element 3 arranged in the filter holder 2. The filter holder 2 can also be referred to as a housing or filter housing. A filter element 3 which is helpful for understanding the invention is shown in FIG Fig. 6 shown. The filter arrangement 1 is preferably used as an intake air filter for internal combustion engines, for example in motor vehicles, trucks, construction vehicles, water vehicles, rail vehicles, agricultural machines or vehicles or aircraft. The filter element 3 is particularly suitable for filtering combustion air from an internal combustion engine. The filter element 3 is preferably an air filter element.

The filter element 3, which can also be referred to as the primary element or main element, comprises a filter body 4 which surrounds a central tube 5 and preferably bears against it in such a way that the central tube 5 can perform a support function for the filter body when it flows through. For example, the Filter body 4 can be wound as a roll from a filter medium onto the central tube 5 or rest against it in a ring-shaped manner, for example in the form of a star-shaped bellows. The central tube 5 is preferably lattice-shaped and therefore fluid-permeable. The filter body 4 is preferably folded. The folded filter medium can be wrapped for stabilization with a thread wrap 6, ie a tape or thread soaked in hot melt adhesive or other adhesive, or fixed by means of circular or spiral adhesive beads. The filter medium is, for example, a filter paper, a filter fabric, a filter scrim or a filter fleece. In particular, the filter medium can be produced in a spunbonded or meltblown process or comprise such a fiber layer applied to a nonwoven or cellulose backing. The filter medium can also be matted or needled. The filter medium can have natural fibers, such as cellulose or cotton, or synthetic fibers, for example made of polyester, polyvinyl sulfite or polytetrafluoroethylene. During processing, the fibers can be oriented in, obliquely and / or transversely or disordered to the machine direction.

The filter element 3 has a first, in particular open end plate 7 and a second, in particular closed end plate 8. The end disks 7, 8 are preferably made of a plastic material. For example, the end disks 7, 8 can be designed as inexpensive plastic injection molded components. The end disks 7, 8 can, for example, be made of a polyurethane material, in particular molded, preferably foamed, in casting shells. The end plates 7, 8 can be cast onto the filter body 4. The filter body 4 is arranged between the end disks 7, 8. A sealing device 10 for sealing the filter element 3 with respect to the filter receptacle 2 is provided on a front side 9 of the first end disk 7 facing away from the filter body 4. The sealing device 10 is set up to seal the filter element 3, in particular radially, with respect to the filter receptacle 2.

The filter medium of the filter body 4 can be fused, glued or welded to the end disks 7, 8. The second end plate 8 is, for example, plate-shaped and preferably impermeable to fluids. A receiving opening 11 is provided in the first end disk 7, through which the air filtered by the filter element 3 can continue to escape. Furthermore, the filter element 3 preferably has an inflow protection 12, which prevents a direct inflow of the filter medium 4 with particle-laden fluid L. The fluid L can be air. The inflow protection 12 can be a film or a close-meshed network or grid. The inflow protection 12 can be fluid impermeable or fluid permeable. The inflow protection 12 can be glued, welded or fused to the filter body 4. The inflow protection 12 is arranged adjacent to the first end plate 7. In particular, the flow protection 12 borders on the first end plate 7. The inflow protection 12 can be connected to the first end plate 7 in particular in a flow-tight manner. Fluid L to be cleaned passes from a raw side RO of the filter element 3 through the filter body 4 into a cavity surrounded by the central tube 5 and flows out of this through the receiving opening 11 as a filtered fluid L onto a clean side RL of the filter element 3 surrounded in particular by the filter body 4.

The filter element 3 preferably has an oval cross section in a longitudinal direction LR thereof. The cross section can decrease starting from the first end plate 7 in the direction of the second end plate 8, so that the filter element 3 tapers. However, the filter element 3 preferably has, as in FIG the Fig. 6 shown for the understanding of the invention, an oval cross-section. That is, the filter element 3 is cylindrical with an oval base surface. In the present case, oval can be understood to mean a shape with a non-concave, smooth outer contour, that is to say consistently of convex and straight sections, preferably formed exclusively of convex sections, for example a rectangular cross section with rounded corners, an elliptical cross section or a cross section formed from several circular arcs. An oval outer contour or a cross section is preferably used which has a center point and two axes of symmetry intersecting in it. The filter element 3 and in particular the filter body 4 have a width b and a height h ( Fig. 10 ) on. The width b is larger than the height h. The width b is preferably two to three times the height h, more preferably the width b is 1.5 to three times the height h.

In the filter holder 2, surrounded by the filter element 3, an in Fig. 7 Secondary element 13 shown may be included. Such secondary elements serve in particular as security for cases in which an operator opens the filter holder 2 and removes the filter element 3 while the machine is running, for example for dust removal or replacement. In particular, the filter element 3 can be referred to as the first filter element and the secondary element 13 as the second filter element. The secondary element 13 is preferably received in the receiving opening 11. The secondary element 13 has a filter medium 14 and a first end plate 15 and a second end plate 16. The filter medium 14 is arranged between the end disks 15, 16. The filter medium 14 surrounds a grid-shaped central tube 17. Like the filter element 3, the secondary element 13 has a raw side RO and a clean side RL. The first end plate 15 can have a sealing device 18 for sealing the secondary element 13 with respect to the filter holder 2. The sealing device 18 can be formed in one piece with the first end plate 15. The filter element 3 and the secondary element 13 can be received in the filter holder 2. The secondary element 13 has a fluid outflow opening 51. The fluid outflow opening 51 can be referred to as the fluid outflow opening of the filter element 3.

As the 1 to 5 show, the filter holder 2 comprises a receiving section 19. The receiving section 19 can be formed from a first housing part 20 and from a second housing part 21. The housing parts 20, 21 can be connected to one another with fastening means 22, such as screws. The housing parts 20, 21 are preferably made of a plastic material. Alternatively, the housing parts 20, 21 can be made of sheet metal, in particular sheet steel. For example, the housing parts 20, 21 can be designed as inexpensive injection molded components. A sealing device such as an O-ring can be provided between the housing parts 20, 21. Alternatively, the receiving section 19 can be formed in one piece. This means that the housing parts 20, 21 form a one-piece component.

Furthermore, the filter holder 2 has a maintenance cover 23 which can be removed from the receiving section 19. The filter element 3 can be removed from the receiving section 19 via the maintenance cover 23. The maintenance cover 23 can be connected to the receiving section 19 by means of quick-release fasteners. A sealing device can be provided between the maintenance cover 23 and the receiving section 19. The Fig. 2 and 3rd show the filter arrangement 1 in two different installation situations, namely in a lying and a standing.

The filter receptacle 2 or the receptacle section 19 has a fluid inlet 24 for the inlet of the fluid L to be filtered into the filter receptacle 2 and a central fluid outlet 25 in particular for the outlet of the fluid L filtered with the aid of the filter element 3 from the filter receptacle 2. The fluid inlet 24 and the fluid outlet 25 are preferably tubular. The fluid inlet 24 can, as in FIGS Fig. 1 , 3rd and 4th shown, have an oval cross-section. With the help of the oval cross-section, the wider extension of which is preferably oriented in the direction of the longitudinal direction LR, a lower initial pressure loss can be achieved in comparison with a circular cross-section. The fluid L to be filtered enters the fluid inlet 24 in an inflow direction E. The fluid outlet 25 preferably has a circular cross section. The fluid L exits the fluid outlet 25 in an outflow direction A, preferably parallel to the longitudinal direction LR of the filter element 3. The inflow direction E is oriented perpendicular to the outflow direction A.

A particle discharge opening 26 can be provided on the maintenance cover 23. The particle discharge opening 26 is preferably tubular. Particles previously separated from the fluid L can be removed from the filter holder 2 via the particle discharge opening 26. The particle discharge opening 26 can have a valve. The housing parts 20, 21 and / or the maintenance cover 23 can be reinforced with ribs.

In the filter receptacle 2 and in particular in the receptacle section 19 there is a first engagement area 27 ( Fig. 5 ) is provided, into which the sealing device 10 of the filter element 3 engages. This engagement area 27 preferably has a sealing contact surface, against which the sealing device 10 can come into contact in a sealing manner. In the present exemplary embodiment, as shown, an oval-cylindrical, radially outwardly directed sealing contact surface is provided, which follows the course of the inner surface 43 (sealing surface) of the sealing device 10. Furthermore, a second engagement region 28 into which the sealing device 18 of the secondary element 13 engages can be provided on the receiving section 19. This second engagement area 28 preferably also has a sealing contact surface 280 (see Fig. 32 ) on which the sealing device 18 can come to rest sealingly. In the present exemplary embodiment, an oval-cylindrical sealing contact surface 280, which is directed radially outward, is provided, as is preferably shown. The first housing part 20 can have the engagement regions 27, 28. The engagement areas 27, 28 can completely circulate around the fluid outlet 25.

The Fig. 8 shows the filter arrangement 1 in a schematic side view. As the Fig. 9 in a schematic sectional view along the section line IX-IX of Fig. 8 shows, the fluid inlet 24 is arranged such that the inflow direction E of the fluid L is oriented in the direction of an outer surface 29 and perpendicular to the longitudinal direction LR of the filter element 3 arranged in the receiving section 19. The lateral surface 29 forms an envelope of the filter body 4. A cylindrical, in particular oval-cylindrical, geometry of the filter element 3 is formed by the end disks 7, 8 and the lateral surface 29. The fluid L to be filtered flows around the filter element 3 which can be accommodated in the receiving section 19 such that particles contained in the fluid L to be filtered are separated on a wall 30 of the filter receptacle 2 or of the receiving section 19 with the aid of centrifugal force. The receiving section 19 thus acts as a centrifugal separator. In particular, the inflow direction E is oriented such that the fluid L to be filtered flows against the filter element 3 essentially tangentially. The receiving section 19 has in Cross section preferably a width direction br and a height direction hr. The width to height ratio br / hr is preferably at least 4: 3, more preferably at least 3: 2, in particular at least 2: 1 and / or at most 6: 1, preferably at most 4: 1, particularly preferably at most 3: 1 or 2: 1. For the purposes of optimized pre-separation, ratios of less than 3: 1 and preferably less than 2: 1 or even less than 1.5: 1 are advantageous. The fluid inlet 24 is preferably arranged such that the inflow direction E is oriented perpendicular to the width direction br, ie preferably perpendicular to the direction of the wider extent.

Because the fluid inlet 24 is oriented such that the inflowing fluid L meets a comparatively more curved curvature 50 of the wall 30 of the receiving section 19, the fluid L to be filtered is strongly accelerated and then flows around the filter element 3 tangentially and in particular helically, spirally or helical. Good particle separation from the fluid L is hereby achieved. The fluid inlet 24 can be shielded by means of a wall 31 from the fluid L flowing around the filter element 3, which supports the formation of a helical flow. The separated particles are removed from the receiving section 19 with the aid of the particle discharge opening 26. The receiving section 19 runs in the longitudinal direction LR of the filter element 3 parallel to the lateral surface 29 of the filter element 3, so that, as in FIG Fig. 10 shown, a constant distance a between the filter element 3 and the wall 30 is provided circumferentially to the longitudinal direction LR around the filter element 3.

The Fig. 11 shows a partial sectional view of the filter arrangement 1. The fluid L to be filtered flows through the fluid inlet 24 into the receiving section 19. Because the inflow direction E of the fluid L to be filtered is oriented in the direction of the lateral surface 29 of the filter element 3 and in particular is also positioned perpendicular to the longitudinal direction LR, the fluid L to be filtered flows around, as in FIG Fig. 11 shown with the help of an arrow 32, the filter element 3 screw-like and flows through the filter body 4 of the filter element 3 in order to flow out again from the fluid outlet 25 of the filter holder 2 in the outflow direction A as filtered fluid L. When the filter element 3 flows around, particles 33 are separated from the fluid L to be filtered on the wall 30 of the receiving section 19 with the aid of centrifugal force and can be removed from the receiving section 19 via the particle discharge opening 26. The particles 33 can, for example, fall out of the particle discharge opening 26 or be sucked out of the latter. Due to the oval cross-sectional geometry of the receiving section 19, compared to a circular cross-section, there is a favorable particle separation with simultaneous suitability of the system for installation spaces with a non-circular or square cross-section.

As the Fig. 11 further shows, the maintenance cover 23 has a tubular, in particular oval tubular, flow protection 48, in which the filter element 3 is at least partially accommodated, preferably in such a way that a flow gap of a few millimeters arises between the filter element and the flow protection. The inflow protection 48 can be formed in one piece with the maintenance cover 23 and in particular prevents particles that have separated out due to the rotating flow from still striking the filter body 4, for example due to the effects of gravity.

The Fig. 12 shows a schematic perspective view of a further embodiment of a filter arrangement 1. The embodiment of the filter arrangement 1 according to FIG Fig. 12 differs from the embodiment of the filter arrangement according to the Fig. 1 only in that the fluid inlet 24 does not have an oval but a circular cross section.

The Fig. 13 shows a schematic perspective view of a further embodiment of a filter arrangement 1. The embodiment of the filter arrangement 1 according to FIG Fig. 13 differs from the embodiment of the filter arrangement 1 according to FIG Fig. 12 in that the fluid inlet 24 is positioned such that the inflow direction E of the fluid L to be filtered is arranged perpendicular to the height direction hr of the receiving section 19, ie perpendicular to the direction of the narrower extension, and not perpendicular to the width direction br thereof.

The Fig. 14 shows a schematic perspective view of a further embodiment of a filter element 3. Die Fig. 15 shows a sectional view of the filter element 3 and the Fig. 16 shows a front view of the filter element 3. In the following, the 14 to 16 referred to at the same time.

The structure of the filter element 3 according to the invention 14 to 16 corresponds essentially to the structure of the filter element 3 according to FIG Fig. 6 . The filter element 3 has a first end plate 7 and a second end plate 8. A folded filter body 4 is positioned between the end disks 7, 8. The end disks 7, 8 are preferably made of cast, in particular foamed polyurethane, which surrounds the filter body in a sealing and form-fitting manner at its axial ends. However, the end disks 7, 8 can also be formed from other materials, such as injection-molded thermoplastic, and, for example, be fused, welded or glued to the filter body 4. The filter body 4 surrounds a grid-shaped central tube 5 or a winding core. To filter fluid L to be cleaned, it flows from a raw side RO of the filter element 3 through the filter medium of the filter body 4 onto a clean side RL of the filter element 3. The first end plate 7 has a receiving opening 11 for receiving a secondary element 13, through which the outflow also occurs of the cleaned fluid takes place according to Fig. 7 on.

The end plates 7, 8 are preferably oval. The filter body 4 can be partially covered by a flow protection 12. The inflow protection 12 can be a fine-mesh grid or a film that is welded, glued or fused to the filter medium. In particular, the flow protection 12 borders on the first end plate 7. The inflow protection 12 prevents particles 33 contained in the fluid L to be filtered that enters through the fluid inlet 24 directly impacting the filter medium.

The second end plate 8 is preferably fluid-tight, so that no fluid L can pass through it from the raw side RO to the clean side RL of the filter element 3. The second end plate 8 can for example have bracing elements 34, of which in the Fig. 15 only one is provided with a reference number. These can be designed as elastically deformable extensions, projecting in the longitudinal direction LR from the end plate 8, which can be supported on the maintenance cover 23 during assembly and are elastically braced by the installation of the maintenance cover 23. The number of bracing elements 34 is arbitrary. With the aid of the elastically deformable bracing elements 34, the filter element 3 can be in the receiving section 19 of the filter holder 2 with respect to a longitudinal direction LR of the Filter element 3 are optimally positioned. The bracing elements 34 also serve to dampen vibrations and / or to compensate for tolerances. The second end plate 8 is preferably formed in one piece with the bracing elements 34. For example, the second end plate 8 can be formed from a polyurethane foam.

On the first end plate 7 and in particular on a front side 9 of the first end plate 7 facing away from the filter body 4, an elastically deformable sealing device 10 is provided for sealing the filter element 3 with respect to the receiving section 19. The sealing device 10 is resiliently deformable. The first end plate 7 and the sealing device 10 are preferably made of one piece of material. For example, the first end plate 7 and the sealing device 10 can be made from a polyurethane foam. The sealing device 10 completely rotates around the first end disk 7. The sealing device 10 is, in particular projected in the longitudinal direction LR, completely within the cross section of the filter body 4.

The sealing device 10 has, as in the Fig. 16 shown, two first convex curvature sections 35, 36 arranged opposite one another. The first curvature sections 35, 36 each have a first radius of curvature R35, R36. The radii of curvature R35 and R36 are preferably of the same size. The radii of curvature R35 and R36 have centers of curvature M35 and M36. The centers of curvature M35 and M36 lie on a common straight line 37.

The sealing device 10 furthermore has two second convex curvature sections 38, 39 arranged opposite one another. The first curvature sections 35, 36 and the second curvature sections 38, 39 are integrally connected to one another. The second curvature sections 38, 39 have second radii of curvature R38, R39. The second radii of curvature R38, R39 are the same. The centers of curvature M38 and M39 of the radii of curvature R38 and R39 lie on a common straight line 40. The straight line 40 is arranged perpendicular to the straight line 37. The straight line 37 has a length a ₃₇ and the straight line 40 has a length a ₄₀ . The straight line 40 preferably divides the straight line 37 in the center and vice versa. The straight line 40 preferably intersects the straight line 37 at a center through which a central axis MA of the filter element 3 runs in the longitudinal direction LR, which preferably lies in overlap with a central axis of the filter holder 2 when the filter element 3 is installed in the filter holder 2. The sealing device 10 also has an outer contour 41. The outer contour 41 does not run parallel to an outer contour 42 of the first end disk 7. The second radii of curvature R38, R39 are larger than the first radii of curvature R35, R36. The secondary element 13 can have a similarly designed sealing device 18.

In Fig. 16 it can also be seen how the contour of the sealing device 10 runs in comparison to a comparison curve VK. The comparison curve VK runs in the specific embodiment shown, as well as particularly preferably parallel to the outer and / or inner contour of the filter body 4 and to the outer and / or inner contour of the open end plate 7 and is further preferably concentric with these. In the middle of the second curvature sections 38, 39, the comparison curve is at the same distance from the outer and inner contour of the filter body 4 and from the outer and inner contour of the open end plate 7 as the inner surface 43 Figure 16 can be seen, the sealing device 10 in its second curvature section 38 more curved than the comparison curve VK. In other words, the second curvature section 38 of the sealing device 10 has a smaller (preferably the smallest) distance to the outer contour of the end plate 7 or the filter body 4 than in the region of the transition from the second curvature sections 38, 39 to the first curvature sections 35 , 36. As also from Figure 16 As can be seen, the geometry described above leads to the second curvature sections 38, 39 of the sealing device 10 projecting into the more curved curvature sections of the end plate 7 or the filter body 4 in an overlap region. In this overlap area UL, the distance of the sealing device 10 or the inner surface 43 from the outer contour of the end plate 7 or the filter body 4 becomes maximum. This allows the width of the end plate 7 to be used in order to design a sealing device 7 that is as strongly curved as possible and thus to achieve a good sealing effect.

As the Fig. 17 and 18th show, the sealing device 10 has an oval-cylindrical inner surface 43 which forms the sealing surface and bears sealingly on the engagement region 27 of the receiving section 19 of the filter receptacle 2, in particular on a corresponding sealing contact surface, when the sealing device 10 engages in the engagement region 27. When engaging in the engagement area 27, the sealing device 10 is resiliently deformed, in particular expanded, in particular in such a way that the bracing of the sealing device 10 against the engagement area 27 is generated exclusively by the resilient deformation. The inner surface 43 lies flat and sealingly against the engagement region 27. With the help of the curved sections 35, 36, 38, 39, a constant contact pressure of the inner surface 43 against the engagement region 27 is achieved all around. As the Fig. 17 further shows, the sealing device 10 can have an approximately rectangular geometry in cross section. Furthermore, the sealing device 10, as in the Fig. 18 shown, have two sealing lips 44, 45, between which a groove-shaped cavity 46 is arranged. In this way, a sealing device 10 that is better protected from external influences can be formed by a tubular web, on the filter receiving side, engaging in the groove-shaped cavity in such a way that the inner and / or outer sealing lip can be sealingly applied to the tubular web. For this purpose, the cavity 46 can preferably be opened axially.

As the Fig. 19 and 32 Show in detail, the sealing device 10 engages in the engagement region 27 of the receiving section 19. Here, the inner surface 43 rests on the engagement region 27, in particular on an oval-cylindrical sealing contact surface 270 there, pointing radially outward (see FIG Fig. 32 ), flat and sealing. The sealing device 10 thus seals the filter element 3 radially inward from the receiving section 19. In the present case, “inside” is to be understood as meaning a direction pointing to the fluid outlet 25.

The Fig. 20 shows a schematic perspective view of a further embodiment of a filter arrangement 1. Die Fig. 21 shows the filter arrangement 1 according to the Fig. 20 in a schematic partial sectional view. The filter arrangement 1 comprises a filter receptacle 2 and a filter element 3 arranged in the filter receptacle 2. A fluid inlet 24 of the filter receptacle 2 is oriented such that an inflow direction E of fluid L to be filtered is oriented in the direction of a longitudinal direction LR of the filter element 3. The fluid inlet 24 is preferably arranged on a maintenance cover 23 of the filter holder 2. Any number of fluid inlets 24 may be provided.

As the 21 to 24 show, each fluid inlet 24 has a guide element 47 for deflecting the fluid L. Each guide element 47 has an angle of curvature α. The guide elements 47 are set up to deflect the inflowing fluid L to be filtered in such a way that, as in FIG Fig. 23 shown with the help of an arrow 32, the filter element 3 flows helically. Here, the filter element 3 is flowed tangentially. As a result, particles 33 are separated on a wall 30 of a receiving section 19 of the filter holder 2 and can be removed from the filter holder 2 via a particle discharge opening 26 of the filter holder 2.

The guide elements 47 can be designed as guide vanes. Preferably, a circumference u ( Fig. 25 ) The filter holder 2 distributes any number of fluid inlets 24. The angle of curvature α of the guide elements 47 can be varied all around the filter element 3, in particular in order to produce a uniformly circulating flow. The maintenance cover 23 can continue in the Fig. 24 have shown tubular inflow protection 48, which is integrally formed with the maintenance cover 23. The inflow protection 48 prevents a direct flow against the filter element 3 with the fluid L to be filtered, in particular by separating the fluid inlets 24 from the filter element 3 in such a way that particles 33 are prevented from directly hitting the filter medium.

The Fig. 25 shows a plan view of the filter arrangement 1. Like the Fig. 25 shows, a plurality of fluid inlets 24 can be provided, of which in the Fig. 25 only two are provided with a reference symbol. An opening cross section of the fluid inlets 24 can vary over the circumference u of the filter receptacle 2. For example, opening cross sections of the fluid inlets 24 can be larger or smaller in areas with a strong curvature of the filter element 3 than in areas of the filter element 3 in which the latter has a small curvature.

The Fig. 26 shows a schematic perspective view of a further embodiment of a filter arrangement 1. Die Fig. 27 shows a rear view of the filter arrangement 1 helpful for understanding the invention. The filter arrangement 1 comprises a filter holder 2. The filter holder 2 according to FIG Fig. 26 differs from the filter holder 2 according to the Fig. 1 through a modified transition section 49.

As the Fig. 27 helpful for understanding the invention, a fluid outlet opening 51 of the filter element 3 is oval and a fluid outlet 25 of the filter holder 2 is circular. The fluid outlet 25 has a circular cross section facing away from the filter element 3 and an oval cross section facing the filter element 3. The circular cross section of the fluid outlet 25 on the side facing away from the filter element 3 preferably has a diameter that is larger than the small diameter of the oval cross section on the side of the fluid outlet 25 facing the filter element 3 and / or larger than the diameter of the sealing device 18 in the smaller dimension (in the height direction hr). As the Fig. 28 and 29 In two schematic sectional views of the filter arrangement 1, a transition between the round fluid outlet 25 and the oval fluid outlet opening 51 of the filter element 3 is achieved by a curved transition section 49 which is arranged between the fluid outlet 25 and the fluid outlet opening 51 of the filter element 3. An advantage of the oval geometry of the fluid outlet opening 51 of the filter element 3 is its large cross-sectional area. Hereby arises despite the in the Fig. 29 shown constriction between the fluid outlet 25 and the fluid outlet opening 51 of the filter element 3 only a slight adverse effect on the pressure loss.

The filter element 3 can, as in the Fig. 30 and 31 shown, continue to taper on the inside, ie a cross section of a filter medium 4 of the filter element 3 increases from a first end plate 7 in the direction of a second end plate 8 of the filter element 3. As a result, an enlarged fluid outlet opening 51 of the filter element 3 can be achieved in comparison to a non-tapered filter body 4.

Reference symbols used:

1

Filter arrangement

2nd

Filter holder or filter housing

3rd

Filter element

4th

Filter body

5

Middle tube

6

Thread wrap

7

End plate, especially open end plate

8th

End plate, especially closed end plate

9

front

10th

Sealing device

11

Receiving opening

12th

Flow protection

13

Secondary element

14

Filter medium of the secondary element

15

End plate of the secondary element, especially open

16

End plate of the secondary element, in particular closed

17th

Middle tube of the secondary element

18th

Sealing device of the secondary element

19th

Receiving section of the filter holder

20

Housing part

21

Housing part

22

Fasteners

23

Maintenance cover

24th

Fluid inlet

25th

Fluid outlet

26

Particle discharge opening

27

Engagement area, in particular for the sealing device 10 of the filter element 3

28

Engagement area, in particular for the sealing device 18 of the secondary element 13

29

Lateral surface, in particular of the filter body 4

30th

Wall, in particular of the receiving section 19th

31

Wall, in particular for flow conduction within the filter holder

32

Arrow, in particular in the direction of flow around the filter element 3

33

particle

34

Bracing element

35

Section of curvature, in particular smaller curvature

36

Section of curvature, in particular smaller curvature

37

Just

38

Section of curvature, in particular larger curvature

39

Section of curvature, in particular larger curvature

40

Straight, especially short middle straight

41

Outer contour, in particular the sealing device 10

42

Outer contour, in particular of the end plate 7 and / or 8

43

Inner surface, in particular the sealing device 10, in particular the sealing surface

44

Sealing lip, in particular with a radially inner sealing edge or sealing surface

45

Sealing lip, in particular with a radially outer or inner sealing edge or sealing surface

46

Cavity, in particular groove between the sealing lips 44, 45

47

Guide element

48

Flow protection, especially on the maintenance cover 23

49

Transitional section, in particular at the fluid inlet 24

50

curvature

51

Fluid outlet opening, in particular through the end plate 15 of the secondary element 13

270

Sealing contact surface of the engagement area 27

280

Sealing contact surface of the engagement area 28

a

distance

A

Outflow direction

a ₃₇

length

a ₄₀

length

b

width

br

Width direction

E

Inflow direction

H

height

Mr

Height direction

L

Fluid

LR

Longitudinal direction

MA

Central axis

M35

Center of curvature

M36

Center of curvature

M38

Center of curvature

M39

Center of curvature

RE

Clean side

RO

Raw side

R35

Radius of curvature

R36

Radius of curvature

R38

Radius of curvature

R39

Radius of curvature

u

scope

UL

Overlap area

VK

Comparison curve

α

Angle of curvature

Claims (8)

1. Filter element (3) for filtering intake air for an internal combustion engine, featuring an oval cross section defined by a filter body (4) of a zigzag folded annularly closed filter medium having two first opposite curved sections of greater curvature connected to one another by two second opposite curved sections of lesser curvature compared to the first curved sections, with an open end disc (7), the filter element (3) further comprising an oval peripheral sealing means (10) for in particular radial sealing of the filter element (3) with respect to a filter receptacle (2), wherein the sealing means (10) is provided on a front side (9) of the end disc (7) facing away from the filter body (4), wherein the sealing means (3) features two oppositely disposed first curved sections (35, 36) with a stronger curvature and two oppositely disposed second curved sections (38, 39) with a smaller curvature than the first curved sections, wherein the second curved sections (38, 39) of the sealing means (10) are more curved than the second curved sections of the oval cross section defined by the filter body (4), wherein the first curved sections (35, 36) are connected to one another by the second curved sections in such a way that the first and second curved sections (38, 39) merge each into one another, wherein the oval course of the sealing means (10) is selected in such a way that it features a center point and two symmetry axes intersecting therein, characterized in that the second curved sections (38, 39) of the sealing means (10) are more strongly curved than a comparison curve (VK) which is essentially parallel, in particular concentric, comparable in terms of their position on the end disc (7) to the inner and/or outer contour (42) of the open end disc (7) and/or filter body (4).
2. Filter element according to claim 1, wherein the second curvature sections (38, 39) of the sealing means (10) are more strongly curved than the inner and/or outer contour (42) of the open end disc (7) and/or of the filter body (4) in the area of the second curvature sections (38, 39).
3. Filter element according to one of the preceding claims, wherein the second curvature sections (38, 39) of the sealing means (10) are more strongly curved than the inner and outer contour (42) of the open end disc (7) and/or of the filter body (4) in the area of the second curvature sections.
4. Filter element according to one of the preceding claims, wherein the first curvature sections of the sealing means and/or of the filter body are each connected to one another by the second curvature sections of the seal or of the filter body in such a way that the first and second curvature sections each merge continuously.
5. Filter element according to one of the preceding claims, wherein the sealing means (10) is disposed in the longitudinal direction (LR) of an imaginary axial continuation of the circumferential surface (29) and/or of the cross section of the filter body (4) and/or of the outer contour (42) of an open end disc (7).
6. Filter element according to one of the preceding claims, wherein the sealing means (10), in particular the inner surface (43) of the seal features, in the central region of the less curved curved sections of the filter body and/or of the sealing means (10), a smaller distance from the circumferential surface (29) and/or the outer contour (42) of an open end disc (7) than in the transition region between strongly and slightly curved sections of the filter body and/or the sealing means.
7. Filter arrangement (1) having a filter seat (2) and a filter element (3) according to one of the claims 1 to 6, which is accommodated in a receiving section (19) of the filter seat (2).
8. Filter arrangement according to claim 7, wherein the receiving section (19) features an engagement portion (27), in which a circumferential sealing means (10) of the filter element (3) engages, and wherein the sealing means (10) abuts with an inner surface (43) on the engagement portion (27).

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